Over time I have been using CTA (1 set @2500mha), Energizer (1 set at 2500mha)and Impact brand (2 sets at 2900mha, 1 set @ 2700mha) rechargeable AAs. I have also used powerex and duracells that have since been retired since they no longer charged. Recently I have noticed that my CTA and Energizers are not fully charging (only getting about 40 to 50 shots before they die). I know they are at least 18 months old. Also I know the Impact batteries are about a year old. I tend to charge every set of batteries I use at least once every two weeks from use (in May which is a really busy month because of high school graduations and firefighting classes here, I went through 24 cycles of the batteries being charged). Also in case it helps to judge my battery useageI have taken close to 22,000 images in the past 18months, plus maybe 100 video clips.

I am looking to replace all my batteries in the next few weeks with fresh new highest capacity MiHM AAs which will be used in a Fuji S9100 anda sunpack superauto 383 flash.

I have been looking on the web at bhphotovideo and thomas-distributing and see that both Pearstone($24.95 for 10 batteries)and Delkin ($12.97 for 4batteries)make 2900mha. I have 2 sets of impact 2900mha batteries now that really last/work well for me. I am hoping they keep working for me but feel sooner or later they will stop charging so I want to make sure I have replacements ready for the day that happens. I have never heard of either brand of batteries and was wondering if anyone has used either of them and how they work for you.

My budget is about $50 and I'd like to get 5 sets total (20 batteries total). Having these5 set of batterieswhen they iused to all fully chargewas enough battery powerto get me through the worest of shooting conditions and assignments. Now I start to worry if I will have enough power available and have come close once to running out.

Any other suggestions if these are not high quaility batteries would also be appreciated. I own 2 NiMH battery chargers already.

The best, and most robust, cells available right now are the Sanyo Eneloop cells. While they don't have super high capacity, they hold up very well and feature a reduced self discharge rate.

High capacity cells tend to be fragile and work fine at first, but their cycle life often falls short of their claims. Once you get above 2700 mAh (which often have a capacity of around 2500 mAh) the capacity claims don't seem to hold up.

Keep in mind that many brands of batteries are not manufactured by the company names on the labels. This means that those who re-label don't necessarily need to be accurate in their claims.

To my knowledge CTA, Energizer, Duracell, Impact, and Powerex do not manufacture NiMh cells. They purchase them from another manufacturer and have their brand names put on them. The more reputable brands have a more realistic label.

A good way to choose a brand is to take a look at the data sheet for the battery. If a data sheet is not available, you will probably have to do your own testing to see if their cells match their claims.

If you must have high capacity cells, Powerex is listed on Thomas Distributing with a warrenty. I am not aware of any other cells that offer a similar warrenty. The Powerex cells have tested out very well, but after a while then tend to develope high rates of self discharge in some cases.

Also, keep in mind that your batteries are only as good as your charger.